Rebels in Sudan's conflict-plagued Darfur region on Tuesday claimed they shot down a military helicopter which the army said crashed because of a malfunction, killing seven.

"Our people attacked this helicopter.... They downed one of them," said Hussain Minnawi, a member of the political bureau in the Sudan Liberation Army faction led by Minni Minnawi.

The attack happened about mid-day on Monday, east of Darfur's Jebel Marra region, he told AFP.

The Russian-made Mi17 transport helicopter went down near El Fasher, the North Darfur state capital, "due to a technical fault while it was on an administrative mission," Sawarmi Khaled Saad, the Sudanese army spokesman, said late Monday.

Seven military personnel died but two other people survived and were being treated in hospital, the state news agency SUNA reported.

At about the same time as the attack claimed by Minnawi, peacekeepers heard heavy artillery and blasts southeast of their base in Tawila, said Christopher Cycmanick of the African Union-United Nations Mission in Darfur (UNAMID).

Fighting appeared to be coming from Kushina village, about 29 kilometres (18 miles) from Tawila, and southwest of El Fasher.

But peacekeepers who tried to reach the area were advised by the government they should not proceed "as heavy fighting was still ongoing," Cycmanick said.

UNAMID could not confirm what caused the helicopter to go down.

Non-Arab tribes in Darfur, Sudan's vast western region, rose up against Khartoum almost 10 years ago in a conflict that the United Nations estimates left at least 300,000 people dead.

Sudan puts the overall death toll at 10,000.

Violence is much lower than its peak in 2003 and 2004 but kidnappings, banditry and clashes between government troops and rebels still occur.

A report this month by the Small Arms Survey, a Swiss-based independent research project, said the military has continued to support ground attacks with aerial bombardment "despite the UN Security Council's prohibition on such offensive aerial operations since 2005."

It said arms supplies to government forces and proxy militias "have been almost entirely unimpeded by the actions and policies of the international community, including the ineffectual UN arms embargo on Darfur."

Rebel weapons are mainly captured from the Sudanese military, it said.

Sudan's President Omar al-Bashir is wanted by the Hague-based International Criminal Court for crimes against humanity, war crimes and genocide allegedly committed in Darfur.

His Defence Minister Abdelrahim Mohammed Hussein is also wanted by the ICC.

Foreign journalists require special permits to visit Darfur, but these are rarely granted.